This invention relates to a laser light emitter to permit an incision, a vaporization of living tissue of animal organisms, or a thermal therapy in case of surgical and internal medical treatments.
Medical treatments such as incisions of living tissue of animal organisms by irradiation with laser light are conspicuous due to the ability of hemostasis during such treatments. It had been the conventional method that the laser light was irradiated from the fore end portion of an optical fiber system which is non-contact with the living tissue, but this method causes severe damage to the fore end portion of the optical fiber. Therefore, a method which has been utilized lately is as follows; at first, the laser light, after being transmitted into an optical fiber system, is fed into an emitting member of a probe being in contact or non-contact with the living tissue (hereafter "living tissue" is sometimes expressed by "tissue" only). Then the laser light emitted from the surface of the probe is irradiated on the tissue.
On the other hand, U.S. Pat. No. 4,273,127 discloses a method of an incision for treated tissue with a laser light emitter comprising a light guide having the form of a knife and a relatively narrow working edge and an optical fiber fixed to a back of the light guide. The treated tissue is incised by the laser light which passes from a tip of the optical fiber through the light guide to the narrow working edge and irradiates from the edge. In this case, the contact between the working edge and the tissue provides tactile feedback to an operator like feedback obtained in mechanical incision.
However, according to this method, a structural distance between the tip of the optical fiber and the working edge causes serious power loss. Therefore, a high output power level of a laser light generator is required.
Moreover, it requires a high accuracy to produce the emitter of this method so that an emitting direction of the laser light from the tip of the optical fiber meets the working edge of the light guide. The emitter is composed of two members; optical fiber and light guide. Accordingly, it is very expensive to produce the emitter.
Further, after being fed into the light guide, the laser light is scattered therein and emitted therefrom. Then, the rate of the laser light emission from the working edge is reduced. Therefore, the laser light generator should have a high output power level for sufficient incisions.
Moreover, the power of the laser light is concentrated on the working edge which meets a center line of a direction oriented by the tip of the optical fiber. And the rate of the laser light emitted from surrounding part of the working edge is extremely reduced. Accordingly, the ability of an incision is influenced by a small change of an angle between a light guide and the incised tissue. As a result, a surgery using this emitter can not be carried smoothly.